1. Technical Field
The present disclosure generally relates to stabilization systems and methods of modifying aircraft with the stabilization systems, and more specifically to modifying the tail booms of helicopters with stabilization systems that alter the aerodynamics of the helicopter.
2. Description of the Related Art
Traditional single rotor helicopters have a main lifting rotor (“main rotor”) that provides a lifting force and a tail rotor that provides a laterally directed force used to counter reaction torque of the main rotor and adjust yaw alignment. As the main rotor passes over the tail boom of the helicopter, the main rotor generates downwash that flows around the tail boom of the helicopter. It is known to include strakes on the approaching side of the tail boom to alter the flow of downwash from the rotating main rotor so as to generate a compensation force that at least partially counteracts the reaction torque produced by rotation of the main rotor. The “approaching side” of the tail boom is the side of the tail boom the main rotor blade approaches during rotation.
For example, U.S. Pat. No. 4,708,305 describes a system for controlling main rotor torque which reduces the power and size requirements of conventional anti-torque means (such as a tail rotor). Torque countering forces are generated by disrupting the main rotor downwash flowing around the fuselage. In particular, the downward flow is separated from the fuselage surface by strakes positioned at specified locations on the approaching side of the tail boom.
U.S. Pat. No. 8,210,468 describes a stabilizer system for a helicopter that includes strakes installed on the approaching side of the tail boom and a modified vertical stabilizer. The components of the stabilizer system cooperate to improve handling of the helicopter (e.g., increased cross wind tolerance), reduce fatigue (e.g., tail boom fatigue, fuselage fatigue, and the like), improve climb performance, improve cruise performance, increase control safety margins, combinations thereof, and the like.